Various magnetic materials exhibit magnetic hysteresis which can be represented on a magnetization curve of a magnetic flux density (B) as a function of the applied magnetic field intensity (H). The size and shape of the hysteresis curve provide measurements of the magnetic properties of the material. Soft magnetic materials are magnetically soft and can be relatively easy to magnetize by applying an external magnetization field. Such soft magnetic materials can exhibit small hysteresis loops, e.g., in which the properties of soft magnetic materials can include a high initial permeability and low coercivity. Hard magnetic materials tend to maintain their initial magnetization and thus are relatively difficult to change their initial magnetization by applying an external magnetization field. Hard magnetic materials can exhibit large hysteresis loops, e.g., in which the properties of hard magnetic materials can include a high remanence, high saturation flux density, and high coercivity. In applications, hard magnetic materials with a high resistance to demagnetization can be used to construct permanent magnets. The area within a hysteresis loop can represent a magnetic energy. The magnetic hysteresis curve of a magnetic material can be used to identify important magnetic characteristics of the material including coercivity (e.g., FL, which is the H value at which B is zero) and magnetic energy product (e.g., (BH)max, which corresponds to the maximum area of a B−H rectangle within the second quadrant (e.g., −H values, +B values) of the hysteresis curve), which can be used as a comparative measure of the magnet strength of a permanent magnet material.
Nanotechnology provides techniques or processes for fabricating structures, devices, and systems with features at a molecular or atomic scale, e.g., structures in a range of one to hundreds of nanometers in some applications. For example, nano-scale devices can be configured to sizes similar to some large molecules, e.g., biomolecules such as enzymes. Nano-sized materials can be used to create a nanostructure, a nanodevice, or a nanosystem that can exhibit various unique properties that are not present in the same materials scaled at larger dimensions and such unique properties can be exploited for a wide range of applications.